Drought management in Kompong Thom, Cambodia: The impact of irrigation on food security

By Paul Wyrwoll

ICEM’s Paul Wyrwoll reports from farming communities in Cambodia, where the recent rehabilitation of the Stung Chinit irrigation scheme has enabled many households to harvest a dry season rice crop and improve their food security.
However, the overall distribution of benefits and costs turns out to be much more complex than he expected.

Rice is the most important crop in Kompong Thom province, as it is across the Lower Mekong Basin. Situated north-east of the Tonle Sap, this province encompasses a large and flat floodplain. Farmers typically rely on a single rice crop, grown during the wet season in a lush landscape of endless rice fields. But in the dry season, the land is transformed into an arid dustbowl. Household food security is contingent on a store of the previous season’s harvest. Alternative income opportunities do exist, but they are limited, meaning that this livelihood cycle is highly precarious for poor households. Food security for families here can be completely undermined by a single adverse event, such as a destructive pest outbreak or the devastating 2011 flood.

The answer to this dramatic shift between rainfall abundance and deficit is well understood: irrigation of fields during the dry season with water from a reservoir, groundwater aquifer, or an alternative water source. But these solutions can be expensive, difficult to maintain, and/or entail external social and environmental costs.

Irrigation: ebbs and flows
Cambodia has a long history of irrigation construction. The long-lived prosperity of the Khmer Empire (AD 802- AD 1431) was founded on an extensive system of canals and reservoirs supplying an abundant agriculture sector. During the late 1970s the Khmer Rouge conscripted almost the entire population to build a vast irrigation infrastructure. The regime envisaged a massive increase in agricultural productivity. In reality, the outcome was very different: forced labour camps led to the death of around 20% of the population and yields never reached the ambitious targets set. Subsequent decades of civil conflict saw the Khmer Rouge’s irrigation systems fall into a state of disrepair.

In 1997, the Asian Development Bank (ADB) and Cambodian Government embarked on a project to rehabilitate one of the Khmer Rouge schemes adjacent to the Stung Chinit River in Kompong Thom. The primary purpose of the project was to reduce poverty by providing farmers with access to water in the dry season. In theory this would mean that they could grow rice or other crops year-round. A large reservoir was built and filled, concrete embankments constructed, and existing dilapidated canals replaced or strengthened. Initially coverage of 7,000 hectares of land was planned; this was subsequently scaled back to 2,960 hectares. Construction began around 2003 and extensions are still continuing today.

ICEM and its local partner, the Enterprise Development Institute (EDI), visited Stung Chinit Irrigation Scheme to find out the answer to two main questions. Firstly, has the irrigation scheme improved the food security of the surrounding villages? And secondly, does the irrigation scheme help farmers to cope with drought, both during the annual dry season and abnormal periods of no rainfall during the wet season?

Village access to water – a complex picture
As we met with the farmers and villagers here, they revealed a huge range of experiences. Overall, communities with access to the scheme have greatly benefited. Their access to water is no longer dependent on rainfall and they can grow more rice and other crops. People living in nearby villages without access to the scheme often feel that they would benefit if they also had greater access to the more abundant and reliable water resources.

Our village lost some land when the reservoir was constructed, but because we can now grow more rice each year with less land we have more food and money than before.

Village Chief, Snoa village

I planted a dry season rice crop in 2012 but because I had to pump water 500m from the river to my field I only just broke even. My neighbours also tried a dry season crop but they lost money.

Mr Hong Sok (62), Kong Meas village

However, access to the scheme is not uniform. Farmers must pay for water to be pumped into their fields. This means that some poorer households living near canals are unable to benefit.

Users of the scheme pay a fee to an organizing committee that oversees operations and conducts maintenance. Many stakeholders are worried that there are insufficient users to contribute the necessary funds for sustaining the scheme. Villages living downstream of the scheme on the Stung Chinit River even told us that the releases from the irrigation reservoir during the wet season may have caused flash floods that has damaged their crops and swept away boats and other fishing equipment.

Overall, a complex and disparate picture emerges from speaking to the people here, raising more questions than answers. The communities we visited were at most only 10km to 15km apart. Yet the experiences of both drought and floods reported by the villagers varied widely. This may be a direct consequence of the irrigation scheme itself, the presence of the mighty and changeable Tonle Sap – or perhaps there are additional factors at work, as yet unknown.

ICEM and EDI are continuing to investigate these issues in greater depth over the coming months, with the aim to gain greater understanding of the complex balance of water resource management, food security and community resilience in Kompong Thom.